Abstract: Transmission of a high frequency signal is provided by a passive mixer. The passive mixer receives a low frequency signal as an input. The passive mixer includes a plurality of transistors each with a gate, a source, and a drain. The passive mixer also includes a local oscillator connected to the gates of the transistors. The gates of the transistors are also connected to a DC bias proportional to the threshold voltage of the transistors. In addition, an output of the passive mixer may be attenuated by a passive attenuator wherein both the passive attenuator and passive mixer are substantially free of quiescent current.

Abstract: A method (1100) and a mobile station (160) for operating in accordance with a discontinuous transmission mode are described herein. The mobile station (160) may include a first time constant generator (340), a second time constant generator (350), and a logic unit (330). The first time constant generator (340) may generate a first time constant in response to a first command from the logic unit (330) whereas the second time constant generator (350) may generate a second time constant in response to a second command from the logic unit (330). The first time constant is greater than the second time constant, which in turn, is associated with the discontinuous transmission mode.

Abstract: A low noise direct conversion transmitter architecture without a post-PA filter is described. A high power/low noise differential LO (110), controlled by a near unity divide ratio PLL (112) for re-modulation protection, is coupled a polyphase quadrature generator (120) generating amplitude-balanced and phase-shifted limited differential LO signals. The quadrature mixers (130 and 132) receive the limited differential LO signals and the filtered differential baseband signals to produce up-converted differential signals. The combiner (168) receives the up-converted differential signals and combines them to produce a differential RF transmission signal. A VCA (174) amplifies the differential RF transmission signal, and the resulting differential signal is converted to a single-ended RF transmission signal through a balun (180). A linear amplifier (184) is coupled to the single-ended RF transmission signal for amplification before radio transmission by an antenna (188).